Why the return is staged, not sudden
After birth the body is still recovering: connective tissue remains affected by pregnancy hormones for a time, the abdominal wall and pelvic floor have been stretched, and tissues from a vaginal delivery or a cesarean incision are healing. Many guidelines reference a roughly six-week postnatal check before resuming higher-impact exercise, but that clearance is a starting gate rather than a green light for full intensity, and timelines differ for cesarean recovery or complications.
Recovery is highly individual, so the same week-by-week plan will not fit everyone.
Rebuilding from the inside out
A common arc rebuilds the deep core and pelvic floor first with breathing and gentle activation, then progresses to bodyweight and light loading, and only later to running and heavier or higher-impact work, often described as a six to twelve month progression to full training. Watching for symptoms such as leakage, heaviness, pain, or abdominal doming guides how fast to progress.
This is general educational information, not medical advice. A postnatal assessment, ideally including a pelvic-health physiotherapist, is recommended before resuming or progressing training.